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Abstract:

The present invention relates to the use of polymer mixtures in the
coating of decorative films and decorative surfaces.

Claims:

1-11. (canceled)

12. Use of low-NMP, aqueous polymer mixture, characterised in that it
contains at least one aqueous polyurethane dispersion based on
polyurethane having a content of Zerewitinoff-active hydrogen atoms from
OH groups and NH groups in the range from 0.01 to 0.25 wt. %, based on
the total amount of polyurethane, and at least one mattifying agent and
at least one crosslinker and/or crosslinker system in the coating of
decorative surfaces and decorative films.

13. Use according to claim 12, characterised in that the polyurethane
dispersion contains as structural components at least one monoalcohol
having a mean molecular weight Mn of from 32 to 145 g/mol and/or at least
one monoamine (g) having a mean molecular weight Mn of from 17 to 147
g/mol.

14. Use according to claim 12, characterised in that the aqueous
polyurethane dispersion contains as further structural components a) at
least one polyisocyanate, b) at least one polyol having a mean molar
weight Mn of from 500 to 6000 g/mol, c) at least one polyol having a
mean molar weight Mn of from 62 to 500 g/mol, d) at least one
compound which contains an ionic group or a group capable of forming an
ionic group, and e) at least one polyamine having a mean molecular weight
Mn of from 32 to 500 g/mol.

15. Use according to claim 14, characterised in that the polyurethane
dispersion contains component c) in amounts of from 1.5 to 23 wt. %,
based on all the structural components.

16. Use according to claim 12, characterised in that the polyurethane
dispersion has a hard segment content of from 28 to 85 wt. %.

17. Use according to claim 14, characterised in that the polyurethane
dispersion contains component b) in amounts of from 10 to 65 wt. %, based
on all the structural components.

18. Use according to claim 12, characterised in that the crosslinker
and/or crosslinker system is based on at least one polyisocyanate and/or
at least one polycarbodiimide.

19. Use according to claim 12, characterised in that the content of NMP
is from 0.0 to 0.5 wt. %, based on the polymer mixture.

20. Use according to claim 12, characterised in that it is free of NMP.

21. Decorative film obtained according to claim 12.

22. Use of a decorative film according to claim 21 in the form of a
dashboard or of a door lining or of an interior lining part or of a seat
covering material.

Description:

[0001] The present invention relates to the use of polymer mixtures in the
coating of decorative films and decorative surfaces.

[0002] Polymer mixtures containing polymer resins, mattifying agents and
crosslinker components are used in the automotive industry in the coating
of decorative surfaces in automotive interiors.

[0003] Polymer resins based on polyurethane are frequently used. Many
polyurethanes contain N-methylpyrrolidone (NMP) as solvent because it is
unreactive towards isocyanate groups and is accordingly suitable for
reducing the viscosity during synthesis of the prepolymer. Moreover, NMP
is capable of dissolving high melting dimethylolpropionic acid, which is
often used in polyurethane dispersion chemistry. The use of NMP ensures
that a sufficient number of hydrophilic centres in the form of
carboxylate groups are incorporated into the polyurethane skeleton in an
economically acceptable reaction time.

[0004] NMP is to be classified as a teratogenic substance, however.
Moreover, it has been shown that NMP and other cosolvents evaporate out
of coatings on decorative surfaces in automotive interiors over time.
Such emissions lead to an increased concentration of NMP and other
harmful cosolvents in the automotive interior, and accordingly to a
health risk for the occupants.

[0005] It was, therefore, an object of the present invention to provide
polymer mixtures whose use in the coating of decorative surfaces in
automotive interiors leads to low or zero emissions of NMP, so that
decorative surfaces that have been coated with such polymer mixtures
satisfy the OEM-specific standards.

[0006] It was a further object of the present invention to provide polymer
mixtures whose use in the coating of decorative surfaces in automotive
interiors leads to low or zero emissions of NMP and at the same time
allows the good properties of decorative surfaces based on conventional
polymer mixtures to be retained, for example a high degree of dullness
with consistently high transparency.

[0007] The above-mentioned objects are achieved by the subject-matters of
the present invention.

[0008] The present invention is directed to the use of low-NMP, aqueous
polymer mixtures which are characterised in that they contain at least
one aqueous polyurethane dispersion based on polyurethane having a
content of Zerewitinoff-active hydrogen atoms from OH groups and NH
groups in the range from 0.01 to 0.25 wt. %, based on the total amount of
polyurethane, and at least one mattifying agent and at least one
crosslinker and/or crosslinker system in the coating of decorative films
and decorative surfaces.

[0009] The polyurethane dispersion preferably has a content of
Zerewitinoff-active hydrogen atoms from OH groups and NH groups in the
range from 0.01 to 0.22 wt. %, particularly preferably in the range from
0.05 to 0.20 wt. %, based on the total amount of polyurethane.

[0010] Hydrogen bonded to N or O is referred to as Zerewitinoff-active
hydrogen (sometimes also only as "active hydrogen") when it yields
methane by reaction with methylmagnesium iodide according to a process
discovered by Zerewitinoff.

[0011] The polyurethane dispersion contains as structural components at
least one monoalcohol (f) having a mean molecular weight Mn of from
32 to 145 g/mol and/or at least one monoamine (g) having a mean molecular
weight Mn of from 17 to 147 g/mol.

[0012] The content of monoalcohols (f) and monoamines (g) is preferably
from 0.1 wt. % to 1.5 wt. %, particularly preferably from 0.1 wt. % to
1.3 wt. %, based on all the structural components of the polyurethane
dispersion.

[0013] The content of NMP is preferably from 0.0 to 0.5 wt. %,
particularly preferably from 0.0 to 0.3 wt. %, most particularly
preferably from 0.0 to 0.1 wt. %, based on the total amount of the
polymer mixture. Yet more preferably, the polymer mixture according to
the invention is free of NMP.

[0014] Within the scope of the present invention, free of NMP means that
the content of NMP in the polymer mixture is less than or equal to the
detection limit (i.e. ≦0.1 ppm) when measured by gas
chromatography.

[0015] The use of the polymer mixtures according to the invention for
coating decorative surfaces or decorative films in automotive interiors
leads to low or zero emissions of NMP and likewise to low or zero
emissions of other cosolvents.

[0016] The polyurethane dispersions used according to the invention have a
low cosolvent content. The polyurethane dispersions used according to the
invention contain preferably from 0.0 to 0.9 wt. %, particularly
preferably from 0.0 to 0.5 wt. %, most particularly preferably from 0.0
to 0.4 wt. %, cosolvents, based on the total amount of the polyurethane
dispersion.

[0017] The polymer mixtures according to the invention have a low
cosolvent content. The polyurethane dispersions used according to the
invention contain preferably from 0.0 to 0.9 wt. %, particularly
preferably from 0.0 to 0.5 wt. %, most particularly preferably from 0.0
to 0.4 cosolvents, based on the total amount of the polyurethane
dispersion.

[0018] Cosolvents within the scope of the present invention are polar
organic solvents. Cosolvents are preferably organic solvents having a
Hansen parameter in the range from 7.2 to 16.0 (cal/cm3)0.5 and
a pKB value >7. Cosolvents are particularly preferably organic
solvents having a Hansen parameter in the range from 7.2 to 16.0
(cal/cm3)0.5 and a pKB value >8. Cosolvents are most
particularly preferably organic solvents having a Hansen parameter in the
range from 7.2 to 16.0 (cal/cm3) and a pKB value >9. The
Hansen parameters are disclosed inter alia in "Polymer Handbooks", Eds.
Brandrup, J; Immergut, E. H. Grulke, E. A., 4th Edition, John Wiley, New
York, 1999, VII/pages 675-711.

[0020] The cosolvents are on the one hand solvents which have already been
used in the synthesis of the polyurethane polymer and on the other hand
solvents which have been added to the polyurethane dispersion
subsequently in order to establish the desired properties.

[0021] The inventively used aqueous polyurethane dispersion contains as
further structural components [0022] a) at least one polyisocyanate,
[0023] b) at least one polyol having a mean molar weight Mn of from
500 to 6000 g/mol, [0024] c) at least one polyol having a mean molar
weight Mn of from 62 to 500 g/mol, [0025] d) at least one compound
which contains an ionic group or a group capable of forming an ionic
group, and [0026] e) at least one polyamine having a mean molecular
weight Mn of from 32 to 500 g/mol.

[0027] The resin of the polyurethane dispersion used according to the
invention preferably has a content of component c) of from 1.5 to 23 wt.
%, particularly preferably from 3.0 to 17 wt. %, and a hard segment
content (HS) of from 28 to 85 wt. %, preferably from 30 to 80 wt. % and
particularly preferably from 32 to 75 wt. %, the amount of isocyanate,
based on the amount of solids, being from 22 to 55 wt. %, preferably from
22 to 50 wt. %, particularly preferably from 22 to 48 wt. %. The acid
number of the solid resin is from 11 to 30 mg KOH/g solid resin,
preferably from 13 to 28 mg KOH/g solid resin and particularly preferably
from 13 to 27 mg KOH/g solid resin.

[0029] Suitable as component a) are the polyisocyanates conventionally
used in polyurethane chemistry, for example diisocyanates of the formula
R1(NCO)2, wherein R1 represents an aliphatic hydrocarbon
radical having from 4 to 12 carbon atoms, a cycloaliphatic hydrocarbon
radical having from 6 to 15 carbon atoms, an aromatic hydrocarbon radical
having from 6 to 15 carbon atoms or an araliphatic hydrocarbon radical
having from 7 to 15 carbon atoms. Examples of preferred diisocyanates are
tetramethylene diisocyanate, hexamethylene diisocyanate,
4,4'-diisocyanatodiphenylmethane, 2,4'-diisocyanatodiphenylmethane,
2,4-diisocyanatotoluene, 2,6-diisocyanatotoluene or
α,α,α',α'-tetra-methyl-m- or -p-xylylene
diisocyanate, as well as mixtures of the mentioned diisocyanates.
Particularly preferred diisocyanates are
1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane (isophorone
diisocyanate) and 4,4'-diisocyanatodicyclohexylmethane.

[0030] Small amounts of, for example, tri- and/or higher-valent
isocyanates can optionally be used in order thus to ensure a specific
degree of branching or crosslinking of the polyurethane. The amount of
polyisocyanate to be used is governed by its functionality and is to be
such that the NCO prepolymer remains stirrable and dispersible. Such
isocyanates are obtained, for example, by reacting divalent isocyanates
with one another in such a manner that some of their isocyanate groups
are derivatised to isocyarturate, biuret, allophanate or uretdione
groups. Such polyisocyanates hydrophilised via ionic groups, as are
conventionally used as crosslinkers in aqueous two-component (2K) PUR
lacquers, are also suitable. Examples of such isocyanates are described
in EP-A 510 438, in which polyisocyanates are reacted with OH-functional
carboxyl compounds. Hydrophilised polyisocyanates are further obtained by
reaction of polyisocyanates with compounds that are reactive towards
isocyanates and carry sulfuric acid groups. Such polyisocyanates have
functionalities of, for example, more than 2.2.

[0031] Suitable polymeric polyols b) have a molecular weight range
(Mn) from 500 to 6000 g/mol, preferably from 500 to 3000 g/mol and
particularly preferably from 650 to 2500 g/mol. The OH functionality is
from at least 1.8 to 3, preferably from 1.9 to 2.2 and particularly
preferably from 1.92 to 2.0. The polyols are, for example, polyesters,
polyethers based on propylene oxide and/or tetrahydrofuran,
polycarbonates, polyester carbonates, polyacetals, polyolefins,
polyacrylates and polysiloxanes. Preference is given to the use of
polyesters, polyethers, polyester carbonates and polycarbonates.
Polyesters, polyethers, polyester carbonates and polycarbonates having OH
functionalities of from 1.92 to 2.0 are particularly preferred. Mixtures
of the described polymeric polyols b) are likewise suitable.

[0032] In admixture with the mentioned polyols b) it is possible to use in
addition also fatty-acid-containing polyesters b1), which are obtained by
esterification or transesterification product(s) of drying and/or
non-drying fatty acids or oils with at least bifunctional polyol
compounds, as are described, for example, in EP-A 0 017 199 (p. 10, 1.27
to p. 11, 1.31). Tetrafunctional hydroxyl components, for example
pentaerythritol, are preferably used as the polyol compounds.

[0033] Likewise suitable as the polyol b1) is partially dehydrated castor
oil, which is obtained by subjecting castor oil to heat with acid
catalysis and is described in EP-A 0 709 414 (p. 2, 1.37-40).

[0034] Likewise suitable as polyols b1) are those which are disclosed in
DE-A 199 30 961 (p. 2, 1.46-54; p. 2, 1.67 to p. 3, 1.3). In that
specification, aliphatic and cycloaliphatic monocarboxylic acids having
from 8 to 30 carbon atoms, for example oleic acid, lauric acid, linoleic
acid or linolenic acid, are reacted with castor oil fatty acid in the
presence of glycerol.

[0035] Also suitable as polyols b1) are transesterification products of
castor oil with one other or a plurality of other triglycerides. The
molar composition of the mixture is thereby so calculated that the mean
OH functionality of the end product is in the range from 1.8 to 2.2.

[0036] Particularly preferred as component b1) are fatty-acid-containing
components which are bifunctional in the statistical mean in respect of
the OH groups and which contain glycerol or trimethylolpropane units.
Most particular preference is given to transesterification products
having mean OH functionalities of 2 of castor oil with a further oil
other than castor oil. The fatty-acid-containing polyesters b1) are
preferably used with polyols b) which have an Mn of from 650 to 2500
g/mol and OH functionalities of from 1.9 to 2. The fatty-acid-containing
polyesters b1) are particularly preferably used with polyols b) which
have an Mn of from 650 to 2500 g/mol, OH functionalities of from
1.92 to 2 and are selected from the group of the esters, ethers,
carbonates and carbonate esters.

[0037] Preferably, the polyurethane dispersion used according to the
invention contains as the polyol only component b) in amounts of from 15
to 72 wt. %, preferably from 20 to 70 wt. % and particularly preferably
from 25 to 68 wt. %, based on the total amount of resin.

[0038] In a further embodiment of the present invention, the polyurethane
dispersion used according to the invention contains components b) and
b1), the total amount thereof being not more than 65 wt. %, measured on
the total amount of resin of components a) to g), and the amount of
component b1), based on the total amount of resin of the polyurethane
dispersion, being from 0 to 30 wt. %, preferably from 0 to 25 wt. %.

[0040] Tri- and higher-functional alcohols of the indicated molecular
weight range can be used concomitantly, proportionately, in an amount
such that the polymer solution remains stirrable. Such components include
trimethylolpropane, trimethylolethane, glycerol and pentaerythritol.

[0041] In admixture with the mentioned polyols c), it is possible to use
in addition also fatty-acid-containing polyesters c1) having molar
weights <500 g/mol, which are obtained by esterification or
transesterification product(s) of drying and/or non-drying fatty acids or
oils having at least bifunctional polyol compounds, as are described, for
example, in EP-A 0 017 199 (p. 10, 1. 27 to p. 11, 1. 31). There are
preferably used as polyols compounds tri- and tetra-functional hydroxyl
components, for example trimethylolethane, trimethylolpropane, glycerol
or pentaerythritol. Likewise suitable are fatty acid amides of fatty
acids/fatty acid chlorides and dialkanolamines, preferably
diethanolamine.

[0042] The amounts of components c) and c1) are such that the sum thereof,
measured on the resin of the polyurethane dispersion, is from 1.5 to 23
wt. %, preferably from 1.5 to 10 wt. % and particularly preferably from
1.0 to 8 wt. %. The weight ratio of c) to c1) ranges from 100:0 to 20:80,
preferably from 100:0 to 30:70 and particularly preferably from 100:0 to
40:60.

[0043] in a preferred embodiment, only component c) is used in amounts of
from 1.5 to 23 wt. %, preferably from 1.5 to 10 wt. % and particularly
preferably from 1.0 to 8 wt. %, measured on the resin of the polyurethane
dispersion.

[0045] Suitable neutralising components for the anionic dispersions are
the tertiary amines known to the person skilled in the art, ammonia, as
well as alkali hydroxides. Preferably, the neutralising component has a
pKB value <7, particularly preferably <6.5 and most
particularly preferably <6.4.

[0050] Suitable solvents for preparing the inventively used polyurethane
dispersion are those which boil below 100° C. at normal pressure,
do not contain groups reactive towards isocyanates and, in addition, are
water-soluble. In addition, it must be possible to remove the solvent
from the prepared dispersion by distillation. Examples of such solvents
are acetone, methyl ethyl ketone, tert-butyl methyl ether and
tetrahydrofuran. Methyl ethyl ketone or acetone is preferably used as
solvent; acetone is particularly preferred.

[0051] The inventively used polymer mixture further contains at least one
mattifying agent. The person skilled in the art makes a distinction
between inorganic and organic mattifying agents. Inorgainc mattifying
agents are, for example, Acematt® from Evonik Degussa/Frankfurt am
Main or Syloid® from Grace/Worms. Organic mattifying agents are, for
example, stearates or polymer-organic mattifying agents (for example
Polymatte® from Stahl Europe/Waalwijk or Astacin®) Novomatt from
BASF/Ludwigshafen). Further mattifying agents are mentioned, for example,
in Karsten: Lackrohstoff-Tabellen, 10th Edition, Vincents Verlag, Hanover
2000. The polymer mixture according to the invention can also contain
combinations of inorganic and organic mattifying agents. Inorganic
mattifying agents are used preferably in amounts of from 0.1 to 6 wt. %,
particularly preferably from 0.5 to 5 wt. %, most particularly preferably
from 1 to 4 wt. %, based on the polymer mixture. Polymer-organic
mattifying agents, based on an aqueous polyurethane dispersion and/or
based on polymer-organic compounds, are used preferably in amounts of
from 0.1 to 75 wt. %, particularly preferably from 0.5 to 60 wt. %, most
particularly preferably from 10 to 55 wt. %, based on the polymer mixture
.

[0052] For crosslinking, all types of crosslinking known to the person
skilled in the art are suitable. Examples which may be mentioned here are
chemical and/or physical types of crosslinking, such as amine
crosslinking, aziridine crosslinking, carbodiimide crosslinking, enamine
crosslinking, epoxide crosslinking, epoxysilane crosslinking, urea
crosslinking, hydrazide crosslinking, melamine crosslinking or oxidative
drying. Self-crosslinking systems, such as azomethine crosslinking, a
carbonyl-amine reaction which takes place by evaporation of the
neutralising agent and of the water, autooxidation or UV-aqueous are also
conceivable. Further possible types of crosslinking are silane
crosslinking and/or radiation crosslinking, for example by means of UV
radiation. Dual-cure crosslinking, that is to say a combination of
polyurethane and UV crosslinking chemistry, is likewise possible. The
mentioned types of crosslinking can be carried out on their own or in any
desired combination.

[0053] As polycarbodiimides there can also be used those modified
according to patent EP0507407. The inventively used polymer mixture
contains preferably from 0.1 to 50 wt. % of at least one crosslinker or
crosslinker system, particularly preferably from 0.1 to 25 wt%, most
particularly preferably from 0.2 to 15 wt. %, based on the polymer
mixture.

[0054] The crosslinker or crosslinker system of the inventively used
polymer mixture is preferably based on a compound selected from the group
consisting of polyisocyanate, polyepoxide, epoxysilane,
alkoxymethylmelamine, urea resin, polycarbodiimide and polyaziridine. A
crosslinker system based on at least one polyisocyanate and/or at least
one polycarbodiimide is particularly preferably used.

[0055] If the polyisocyanate forms the basis of the crosslinker or
crosslinker system, the polyisocyanate preferably has an NCO content of
from 5 to 30 wt. %, particularly preferably from 7 to 25 wt. %.

[0056] The polyisocyanate can be a polyisocyanate selected from the group
consisting of hexamethylene diisocyanate (HDI), isophorone diisocyanate
(IPDI), 4,4'-dicyclohexylmethane diisocyanate (H12MDI) and
hexahydrotoluene diisocyanate (H6TDI), it being possible for each of
these polyisocyanates to be present in the form of the biuret or
uretdione or allophanate or isocyanurate or iminooxadiazinedione.

[0057] The NCO content, prior to crosslinking, of the inventively used
polymer mixture crosslinked by the crosslinker or crosslinker system is
preferably from 0.1 to 9.0 wt. %, particularly preferably from 0.1 to 8.0
wt. %, most particularly preferably from 0.1 to 5.0 wt. %.

[0058] The inventively used polymer mixture contains preferably from 0 to
75 wt. %, particularly preferably from 1 to 70 wt. %, most particularly
preferably from 5 wt. % to 65 wt. %, diluent The diluent is water and/or
low molecular weight alcohols or a mixture thereof in variable
proportions by weight. Preferred low molecular weight alcohols are
selected from the group consisting of ethanol, propanol, isopropanol,
n-butanol and isobutanol. A mixture of water and isopropanol is
particularly preferably used as diluent.

[0059] The polymer mixture further contains preferably from 0 to 40 wt. %,
particularly preferably from 0 to 30 wt. %, most particularly preferably
from 0 to 20 wt. %, of at least one lubricant.

[0060] The lubricant is one and/or more compounds selected from the group
consisting of polydialkylsiloxane, polydimethylsiloxane (PDMS), modified
polysiloxanes, branched polyorganosiloxanes, polyolefinic waxes,
polyamide waxes, polytetrafluoroethylene (PTFE), alternating
ethylene-chlorotrifluoroethylene copolymers (ECTFE), perfluorinated
alkoxy resins (PFA) and natural waxes, for example carnauba waxes. It is
particularly preferred, however, for the non-functionalised lubricant to
be a polydimethylsiloxane and to have from 10 to 14,000 D-silicone
structural units.

[0067] Functionalised lubricants can also be used alternatively or in
combination, at least one functionalised and modified polysiloxane
lubricant being preferred. The functionalised lubricant is modified with
primary and/or secondary and/or tertiary amino groups and/or OH groups.

[0068] The functionalised lubricant preferably has an amine number from
0.1 to 3.0 mg KOH/g and/or an OH content from 0.3 to 5.0 wt. %.

[0077] The polymer mixture is used on the decorative surface preferably as
a top and/or lacquer layer for the decorative surface, it also being
possible for the lacquer layer to consist of one or more identical or
different polymer mixtures. In order to adjust the technical properties,
for example the friction behaviour, the surface feel, in particular the
surface feel to the touch, the rheology, the dulling behaviour, and the
light and heat resistance, various crosslinker components, mattifying
agents and additives, also referred to as further added ingredients, are
added to the polymer mixture. The addition of the added ingredients takes
place, according to the OEM specification, in different parts by weight
relative to one another. This procedure is known to the person skilled in
the art.

[0078] The polymer mixture according to the invention is used as a coating
on decorative films for mouldings or on mouldings. Preferred applications
of such decorative films are dashboards or door linings or interior
lining parts or seat covering material in a vehicle.

[0079] The resulting overall dry layer thickness over all the layers is
from 0.5 to 50 g/m2, preferably from 1 to 35 g/m2.

[0080] The inventively used polymer mixture can be applied in the known
manner, for example by spread coating, pouring, knife application,
spraying, spin coating, roller coating or dipping.

EXAMPLES

[0081] Method for determining the molar weights the following GPC
equipment (calibrated to polystyrene standard) was used.

[0093] Method for Determining NMP and Other Cosolvents in a Polymer
Mixture 100 mg or 10 μl of the sample to be tested are weighed into a
20 ml headspace bottle, which is sealed with PTFE-lined butyl septums.
There are further prepared 5 calibrations of the cosolvents used in
various compositions, which are, however, to lie within the range of the
desired concentration of the substances to be tested.

[0094] The samples are processed in a gas chromatograph (e.g. GC Clarus
500 with headspace device HS 40 from PerkinElmer/Juggesheim).

[0113] Evaluation: For each cosolvent, the gradient is calculated from the
calibrations. Using the corresponding gradient, the amount is calculated
for each solvent and then converted to the percentage composition.

[0114] Method for Determining NMP and Other Cosolvents in a Film

[0115] 1 cm2 of the film to be tested is weighed into a 22 ml
headspace bottle, which is sealed with PTFE-lined butyl septums. 4
injections are carried out per headspace bottle. The samples are
processed in a gas chromatograph (e.g. GC Clarus 500 with headspace
device HS 40 from PerkinElmer/Juggesheim):

[0134] Evaluation: From the peak areas of the 4 injections, the total peak
area for each component to be determined is calculated so that, after
calibration with the component to be determined, a quantitative result is
obtained.

[0135] Method for Determining the Degree of Gloss of a Polymer Mixture

[0136] The finish test film is placed smoothly on the vacuum plate of the
Coatmaster and the vacuum is switched on. The polymer mixture is applied
as a wet film of defined thickness to the finish test film by means of a
film applicator and the Coatmaster. The film is then dried for 3 minutes
at 130° C. In a circulating air oven. After drying and cooling to
room temperature, the degree of gloss of the film is measured by means of
a reflectometer.

[0144] The polymer mixture is to he described in greater detail by means
of an Implementation Example A, consisting of a base lacquer and a
finishing lacquer, and corresponding test results.

[0145] Preparation of Polyurethane Dispersion Type 1

[0146] Preparation of the fatty-acid-containing polyester: 3200 g of
castor oil and 1600 g of soybean oil as well as 2.0 g of dibutyltin oxide
were weighed into a 5-litre reactor having a fractionating column. A
stream of nitrogen (5 l/h) was passed through the reactants. The mixture
was heated to 240° C. In the course of 140 minutes and, after 6
hours at 240° C., was cooled, the OH number was 108 mg KOH/g, the
acid number was 2.5 mg KOH/g.

[0147] 119.4 g of the fatty-acid-containing polyester, 40.7 g of polyether
(polypropylene oxide, OH number 112), 29.9 g of dimethylolpropionic acid,
11.9 g of coconut oil fatty acid diethanolamide and 12.8 g of
1,6-hexanediol were mixed and heated to 55° C. 150. g of acetone
and 231.7 g of Desmodur® W were added in succession to the mixture,
and boiling was carried out under reflux until an NCO content of 5.1 wt.
% was reached. The mixture was again adjusted to 55° C., and 16.9
g of triethylamine, which had been stirred thoroughly, were added to the
clear solution. The whole of the neutralised prepolymer solution
(55° C.) was dispersed, with vigorous stirring, in 776.6 g of
water, which was at a temperature of 30° C. After the dispersion,
stirring was carried out for a further 5 minutes before a solution of
11.8 g of ethylenediamine, 0.5 g of diethylenetriamine and 7.8 g of
diethanolamine, dissolved in 73 g of water, was added in the course of 5
minutes. Thereafter, the acetone was removed by distillation in vacno
(120 mbar) at 40° C. In order to react the reamining isocyanate
groups, the mixture was stirred at 40° C. until no further NCO was
detectable by IR spectroscopy. After cooling to 30° C., filtration
through a 240 μm rapid filter was carried out.

[0148] Characteristic Data of the Polyurethane Dispersion:

[0149] Solids content: 35%

[0150] Hard segment content: 64%

[0151] Acid number (based on solid resin): 28.0 mg KOH/g

[0152] Mn (GPC)=20.124 g/mol

[0153] NH content=0.15%

[0154] Preparation of Polyurethane Dispersion Type 2

[0155] 152.1 g of Desmodur® W and 348.7 g of Desmodur® I were
heated to 55° C. and stirred. 62.2 g of dimethylolpropionic acid
were then added. After 5 minutes, a solution of 470.4 g of Desmophen®
C 1200, 96.3 g of neopentyl glycol, 2.8 g of butyl glycol and 377.5 g of
acetone was added in the course of 20 minutes, and the mixture was heated
to 68° C. Stirring was carried out at that temperature until an
NCO content of 2.8% was reached. Thereafter, the mixture was cooled to
60° C., and 46.9 g of triethylamine were added. 450 g of this
solution were dispersed, with vigorous stirring, in 545.9 g of water,
which was at a temperature of 35° C. After the dispersion,
stirring was carried out for a further 5 minutes. A solution of 2.0 g of
diethylenetriamine, 1.1 g of n-butylamine and 3.5 g of ethylenediamine in
60.7 g of water was then added in the course of 10 minutes, When the
addition was complete, stirring was carried out for 20 minutes at
40° C. before the acetone was removed by distillation in vacuo at
that temperature. In order to react the isocyanate groups completely,
stirring was carried out at 40° C. until no further NCO was
detectable by IR spectroscopy. After cooling to <30° C.,
filtration was carried out over a 240 μm rapid filter from Erich
Drehkopf.

[0156] Characteristic Data of the Polyurethane Dispersion:

[0157] Mean particle size (LCS):

[0158] pH (solids diluted, to 10 wt. %): 7.9

[0159] Solids content: 35.9%

[0160] Acid number (based on solid resin): 22.5 mg KOH/g

[0161] Hard segment content: 59.3%

[0162] Mn (GPC)=12.048 g/mol

[0163] NH content=0.25%

[0164] Preparation of Polyurethane Dispersion Type 3

[0165] 62.0 g of Desmodur ® W and 142.0 g of Desmodur® I were
heated to 55° C. and stirred. 37.7 g of dimethylolpropionic acid
were then added. After 5 minutes, a solution of 470.5 g of Desmophen®
C 1200, 15.6 g of neopentyl glycol, 1.1 g of butyl glycol and 243 g of
acetone was added in the course of 20 minutes, and the mixture was heated
to 68° C. Stirring was carried out at that temperature until an
NCO content of 1.8% was reached. Thereafter, the mixture was cooled. to
60° C., and 27.2 g of ethyldiisopropylamine were added. The
solution was dispersed, with vigorous stirring, in 807 g of water, which
was at a temperature of 35° C., After the dispersion, stirring was
carried out for a further 5 minutes. A solution of 1.8 g of
diethylenetriamine, 1.0 g of n-butylainine and 3.3 g of ethylenediamine
in 72 g of water was then added in the course of 10 minutes. When the
addition was complete, stirring was carried out for 20 minutes at
40° C. before the acetone was removed by distillation in vacuo at
that temperature. In order to react the isocyanate groups completely,
stirring was carried out at 40° C. until no further NCO was
detectable by IR spectroscopy. After cooling to <30° C.,
filtration was carried out over a 240 μm rapid filter from Erich
Drehkopf.